1. Field of the Technology
The present disclosure is directed to cutting tool systems, cutting inserts, and tool holders. Certain embodiments described in the present disclosure are directed to generally parallelogram-shaped replaceable and indexable cutting inserts and to cutting tool systems including the cutting inserts.
2. Description of the Background of the Technology
Cutting inserts used in peripheral rotary milling typically are generally parallelogram-shaped. These inserts have a generally parallelogram-shaped profile when viewed from a point above the top surface of the cutting insert, with two long sides forming two main or “radial” cutting edges, and two short sides forming two minor or “axial” cutting edges. As compared with other types of cutting inserts for peripheral rotary milling, generally parallelogram-shaped cutting inserts have a more positive cutting geometry and provide more efficient machining because the inserts' long radial cutting edges provide a larger depth of cut.
Current designs of generally parallelogram-shaped cutting inserts are complex in geometry, and the associated tool holders, on which the inserts are mounted, typically are cylindrical in shape, allowing a plurality of the inserts to be mounted about the outer periphery of the tool holder body. Generally parallelogram-shaped cutting inserts are commonly available in sets or “families”, where each family member has substantially the same width and certain other common geometric characterisitics, but includes a different corner nose radius. Thus, a family of inserts may comprise several inserts, and each such insert has a gradually increasing corner nose radius. Corner nose radii within a family of parallelogram-shaped rotary milling inserts typically may be from 0.2 mm up to 6.4 mm or more, depending on the particular insert width of the family. Certain parallelogram-shaped cuffing inserts adapted for peripheral milling applications, for example, have corner nose radii as large as 8 to 10 mm.
The present inventors have discerned that a deficiency in existing tool systems utilizing generally parallelogram-shaped cutting inserts is that several different tool holders may be required to accommodate all of the inserts in a single insert family. As discussed below, this requirement typically results from the fact that substantial differences in corner nose radius between conventional inserts in a given family require different insert pocket geometries, even though the width of each insert within the family is substantially identical. A conventional tool holder adapted for holding generally parallelogram-shaped cutting inserts having a relatively small corner radius cannot be used to securely hold an insert in the same family having a substantially larger corner nose radius. This incompatibility may require an operator to change tool holders when machining using two or more inserts within a given family, resulting in machine tool downtime and consequent productivity losses. Tool holder manufacturers and distributors also must manufacture and/or stock multiple tool holders to accommodate a given insert family, which diverts limited resources and complicates sales and distribution efforts.
Therefore, a need exists for an improved cutting tool system for peripheral rotary milling wherein a single tool holder able can accommodate and securely retain an entire family of generally parallelogram-shaped cutting inserts having a range of significantly varying corner nose radii. The present inventors disclose herein a unique system adapted to satisfy this unmet need. It is believed that the novel cutting tool system and cutting inserts disclosed and claimed herein will have a considerable positive economic impact on cutting tool manufacturers and distributors, and on cutting tool end users.